How to measure stair stringers for your deck

So, your deck is ready for summer lounging. Now, all you need is the stairs to get to it. But before you jump in and buy your stair stringers and treads, you need to calculate how many steps you’ll need to reach from the deck to the ground. Here’s a simple but helpful guide on how to measure stair stringers and our trusty calculator.

Note: If your calculation is a decimal number, you’ll need to round to the nearest whole number. If you’re in between sizing, check out our blog on how to cut your stringers or increase the ground-level height.

The following diagram shows how to measure the distance from your deck to the ground so you can determine the rise and run of your stair stringers. The measurements you’ll need are:

1. Total rise: The overall height of the stairs
2. Total run: The overall length of the stairs
3. Stair rise: The height of each step
4. Stair run: The length of each step

• A level
• Tape measure
• Calculator
• Pencil and paper

To get this project started, you need to measure the total rise. Place your level on the edge of your deck so that it overhangs. Measure from the bottom of the level to the ground with your tape measure.

Note: If your deck is incomplete and doesn’t yet have deck boards, place one between the deck frame and the level to get the correct total rise measurement.

To determine the number of steps, divide the total rise by the stair rise. EziStep stairs have a rise of 160mm. Because your deck or porch acts as the last step, you’ll need one less tread.

• For example: if your total rise is 480mm and your stair rise is 160mm, you need 2 steps. (480 ÷ 160 – 1 = 2) 

With the stair rise settled, the next measurement you need is the stair run. The stair run measures the stair tread, which is the horizontal board that you place your foot on. Our EziStep stair treads are 240mm in length.

Time for more math. Calculate the total run of the stairs by multiplying the number of stairs by the stair run. In our example, the calculation will look like this:

• Stair run (240mm) x Total number of stairs (2) = 480mm

For any DIY project, having a visual reference is always beneficial. Make a sketch that includes all your measurements. Keep it as close to scale as possible for clarity. That way, you’ll know exactly how many EziStep stringers and treads are needed for your deck.

And if you’re still unsure, simply take your sketch to your local Bunnings store, and their expert staff will be able to help!

Now that you have all the information you need to measure your stair stringers, drop by your nearest Bunnings Warehouse. You’ll find EziStep stair stringers and treads that are perfect for your decking project. You can also get them in a handy kit that comes with everything you need.